Electrical connector



R. D. CARGILL ETA]. 3,104,927

Sept. 24, 1963 ELECTRICAL CONNECTOR 2 Sheets-Sheet 1 Filed Nov. 25, 1960FIG. 3

ATTORNEY Sept. 24, 1963 R. D. CARGILL ETAL 3, ,9

ELECTRICAL CONNECTOR I Filed Nov. 25, 1960 2 Sheets-Sheet 2 v UnitedStates Patent 3,194,927 ELECTRICAL CONNECTOR Roger D. Cargili, Endicott,and Arthur W. Northrop,

Oakdale, N.Y., assignors to international Business Machines Corporation,New York, N.Y., a corporation of New York Filed Nov. 25, 1960, Ser. No.71,813 3 Claims. ((31. 339256) This invention relates to electricalterminals or connectors of a type adapted to slip into a contact elementprojecting from a receptacle and, more particularly, to electricalconnectors which are crimped onto the end of electrical conductors andare adapted to slip onto projecting contact elements in a manner thatthe projecting contact element extends through the gripping portion ofthe associated connector so as to accommodate one or more connectors.

The connector of the present invention is particularly useful forconnecting electrical conductors to contact elements projecting fromreceptacles for receiving pluggable units. Heretofore, a rather commonpractice for connecting electrical conductors to projecting contactelements was to wrap the electrical conductors in a spiral fashion aboutthe projecting contact elements. While the wrapped wire connectiongenerally produces a satisfactory connection, it requires a special toolfor making the connection and another special type of tool fordisconnecting the wire from the associated contact element. Further, thewrapped wire connection is a rather permanent type of connection anddoes not lend itself to use in those areas where the electricalconnections, for example, within a data processing machine, must bechanged quite frequently.

The connector in the present invention is mechanically and electricallyreliable and is specially adapted for use where the electricalconnections with the projecting contact elements must be changed quitefrequently. A type of projecting contact element for which the connectorof the present invention is particularly suitable is that type shown anddescribed in copending application Serial No. 752,038 to A. H. Johnson,filed July 30, 1958, Patent No. 3,008,113, granted November 7, 1961. Inthat application, the electrical conductors are connected to theprojecting contact elements by wrapping the electrical conductors aboutthe contact elements. The contact elements project sufiiciently topermit several electrical conductors to be wrapped about a singlecontact element, and are of the type of contact elements commonly knownas the spade type.

The connector of the present invention has a contact element grippingportion spaced from the central axis of the electrical conductor towhich the connector is attached. By this arrangement, several connectorsmay be slipped onto a single projecting contact element and withoutresorting to a piggyback type of arrangement. The facility of having theconnectors in line on a single contact element permits contact elementsto be closely spaced relative to each other.

Accordingly, the prime object of the invention is to pro vide anelectrical connector of the slip-on type which is mechanically andelectrically reliable.

Another object of the invention is to provide an improved electricalconnector which is adapted to slip onto a contact element with thecontact element extending through the contact portion of the connectorso as to permit additional connectors to be inserted thereon in line.

Another object of the invention is to provide an improved electricalconnector which is effectively of the closed entry type.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments 3,104,927 Patented Sept. 24, 1963of the invention, as illustrated in the accompanying drawllHgS.

In the drawings:

FIG. 1 is a perspective view showing several connectors slipped onto acontact element projecting from a receptacle;

FIG. 2 is a plan view of the connector prior to being attached to anelectrical conductor;

FIG. 3 is a side elevational view of a connector detached from anelectrical conductor;

FIG. 4 is a left-end elevational view of the connector;

FIG. 5 is a sectional view taken along the line 55 in FIG. 4 and lookingin the direction of the arrows;

FIG. 6 is a sectional view showing a contact element inserted into theconnector;

FIG. 7 is a sectional view taken along the line 7-7 in FIG. 3 andlooking in the direction of the arrows;

FIG. 8 is a plan view of the blank from which the connector is formed;

FIG. 9 is a right-end elevational view of the blank from which theconnector is formed;

FIG. 10 is a sectional view of another embodiment of the connector;

FIG. 11 is a side elevational view of a preferred embodiment of theconnector;

FIG. 12 is a plan view of the connector shown in FIG. 11; and,

FIG. 13 is a sectional view taken along the line 13-13 and looking inthe direction of the arrows in FIG. 12.

With reference to the drawings and particularly to FIG. 1, the inventionis illustrated by way of example as a connector 10 having a contactelement gripping portion 11, a conductor embracing furrow 12 and aninsulation embracing furrow 13 attached to a conductor 14. The connector10 is shown with the contact element grip ping portion 11 in positionand embracing or clasping the contact element 15 of a receptacle 16. Thereceptacle 16 is of the type having a plurality of contact elements 15projecting therefrom :and each including a portion within the receptaclefor making contact with the terminals on a pluggable element, not shown,which is insertable into the receptacle 16.

The connector 1% is formed from a blank shown in FIG. 8. The blank fromwhich the connector 10 is formed may be of any suitable electricallyconducting material such as phosphor bronze and is suiliciently hard andresilient to give a spring quality to the contact element grippingportion 11. The insulation embracing furrow 13 and the conductorembracing furrow 12 are formed in the usual manner to take theconfiguration of a U, as seen in FIG. 4. When the connective end is tobe attached to the conductor 14, the furrows 12 and 13 are cold forgedor crimped onto the conductor 14 so that the furrow 12 makes amechanical and electrical connection with th conductor and the furrow 13mechanically embraces the insulation surrounding the conductor 14.

The contact element gripping portion 11 consists of opposed sides 20 and21 integral with and extending from a base portion 22, as seen in FIGS.6 and 7. Each side 20 and 21 is provided with a tab or arm 23 and 24extending substantially at right angles from the associated side tooverlie the upper face of the opposed side, as seen in FIGS. 2 and 7.Guide lances 26 and 27 are formed from the sides 20 land 21,respectively. The lances 26 and 27 function to restrict the contactelement from traveling inwardly toward the base 22. If the contactelement 15 were permitted to travel toward the base 22, the connector 10would be subjected to an overstressed condition resulting in a loss ofmechanical and electrical contact qualities. Additionally, it is seen inFIG. 10 the lances 26 and 27 are also adapted to function to makecontact 'posed sides 20 and 21.

with the contact element 15. The width of the contact element 15 isgreater than the distance between the sides 20 and 21, as seen in FIG. 4and FIG. 5. To facilitate insertion of the connector over the contactelement from either end, the upper corners 28 and 29 of side and uppercorners 30 and 31 of side 21 are beveled suifi ciently and, in thisexample, approximately 15. As the connector 10 is inserted over thecontact element 15, forces are developed to deflect sides 20 and 21 awayfrom each other. The insertion pressure is reduced by the gradualdeflection of sides 20 and 21. Contact is established between thecontact element 15 and connector 10 as shown in either FIG. 6 or FIG.10, depending upon the formation of the lances 26 and 27. In F1G, 6, thelances 26 and 27 function to guide the contact element 15 into thecontact gripping portion 11 and prevent the contact element 15 fromtraveling toward the base 22. The lances 26 and 27 in FIG. 10 performthe same function as lances 26 and 27 in FIG. 6 but, additionally, theymake contact with the contact element 15.

The arms 23 and 24 prevent the contact element 15 from sliding off thesides 20 and 21 during and/or after insertion of the contact element 15into connector 10. By forming the arms 23 and 24 so as to extend inopposite directions and to overlap the corresponding sides 20 and 21,respectively, a closed entry-type of connector is effectively achieved,thereby resulting in good mechanical and electrical qualities.

The connector shown in FIGS. 11, 12 and 13 is a preferred embodiment. Inorder to aid the arms 23 and 24 from taking a permanent set due to anyoverstressing which might occur when the contact is slipped onto theterminal 15, stabilizing ribs 33 and 34 are provided as shown in FIG.11. The ribs 33 and 34, which stabilize and strengthen the sides 20 and21, are spaced from each other and are formed in the .base portion 22and the op- The ribs 33 and 34 are formed as the connector 10 is formedfrom the blank shown in FIG. 8. The ribs 33 and 34 project or extendinwardly of the sides 20 and 21 and base 22. The ribs 33 and 34 extendup the sides 20 and 21, as seen in FIG. 13, to the line of contact ofthe contact element 15 with the connector 10. Thusly, the ribs 33 and 34provide additional resilience in the sides 20 and 21 to increase thecontact and withdrawal forces of the connector 10.

From the foregoing, it is seen that a connector is provided which isadapted to slip onto a contact element in a manner to permit a like oranother type of slip-on connector to be also inserted onto the samecontact element. The contact gripping portion of the connector is out ofthe plane of the connector furrow portion, which attaches onto theelectrical conductor. Hence, the contact element gripping portion of oneconnector can be positioned to overlie the furrow portion of anotherconnector positioned to embrace the same contact element.

. While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled'in the art that the foregoing and other changes in formand details may be made therein without departing from the spirit andscope of the invention.

What is claimed isz 1. An electrical connector for connecting aconductor to a single spade-type contact element of predeterminedlength, said contact element having two major and minor contactingsurfaces along the length thereof, comprising:

a base member;

a pair of opposed side members extending from said base member, saidside members (:2) having a longitudinal dimension less than half of saidpredetermined length of said contact element, whereby said contactelement can extend through said connector and protrude therefrom overmore than one-half of its length, and

'(b) being normally separated a distance less than the width of saidspade-type contact element so as to clasp said spade-type contactelement along the minor contacting surfaces thereof by the re silientspring force of said side members;

a pair of guide lances projecting angularly from said side memberstoward each other and away from said base member to prevent said contactelement [from traveling toward said base member;

a pair of arms spaced along the longitudinal axis of said connector andextending from said opposed side members beyond a center plane drawnperpendicular to said base member half-way between said opposed sidemembers, whereby said pair of arms and said pair of guide l ancescooperate to define a longitudinal channel for receiving and cradlingsaid spade-type contact element; and

axially offset means connected to said base member for holding saidconductor, said oiiset means being spaced from the longitudinal axis ofsaid channel so as to leave space for a second connector to be slippedonto said protruding contact element.

2. An electrical connector as in claim 1 wherein said guide lancesproject in a manner to abut against said contact element.

3. An electrical connector as in claim 1 wherein a pair of continuousribs longitudinally spaced from each other are formed in said base andside members, said ribs being disposed in line with said pair of armsand extending upwardly of said side members to the line of contact madebetween said side members and said contact element.

References Cit d in the file of this patent UNITED STATES PATENTS564,679 Wurts July 28, 1896 2,346,166 Hurleman Apr. 11, 1944 2,478,143Watts Aug, 2, 1949 2,591,009 Riche Apr. 1, 1952 2,659,063 Webb let a1Nov. 10, 1953 2,705,788 Soreng Apr. 5, 1955 2,765,452 Tuchel Oct. 2,1956' 2,825,883 Batcheller Mar. 4, 1958 2,917,723 Gluck Dec. 15, 19592,992,404 Berg July 11, 1961 3,021,503 Hopkins et al Feb. 13, 1962FOREIGN PATENTS 155,717 Great Britain Dec. 30, 1920

1. AN ELECTRICAL CONNECTOR FOR CONNECTING A CONDUCTOR TO A SINGLESPADE-TYPE CONTACT ELEMENT OF PREDETERMINED LENGTH, SAID CONTACT ELEMENTHAVING TWO MAJOR AND MINOR CONTACTING SURFACES ALONG THE LENGTH THEREOF,COMPRISING: A BASE MEMBER; A PAIR OF OPPOSED SIDE MEMBERS EXTENDING FROMSAID BASE MEMBER, SAID SIDE MEMBERS (A) HAVING A LONGITUDINAL DIMENSIONLESS THAN HALF OF SAID PREDETERMINED LENGTH OF SAID CONTACT ELEMENT,WHEREBY SAID CONTACT ELEMENT CAN EXTEND THROUGH SAID CONNECTOR ANDPROTRUDE THEREFROM OVER MORE THAN ONE-HALF OF ITS LENGTH, AND (B) BEINGNORMALLY SEPARATED A DISTANCE LESS THAN THE WIDTH OF SAID SPADE-TYPECONTACT ELEMENT SO AS TO CLASP SAID SPADE-TYPE CONTACT ELEMENT ALONG THEMINOR CONTACTING SURFACES THEREOF BY THE RESILIENT SPRING FORCE OF SAIDSIDE MEMBERS; A PAIR OF GUIDE LANCES PROJECTING ANGULARLY FROM SAID SIDEMEMBERS TOWARD EACH OTHER AND AWAY FROM SAID BASE MEMBER TO PREVENT SAIDCONTACT ELEMENT FROM TRAVELING TOWARD SAID BASE MEMBER; A PAIR OF ARMSSPACED ALONG THE LONGITUDINAL AXIS OF SAID CONNECTOR AND EXTENDING FROMSAID OPPOSED SIDE MEMBERS BEYOND A CENTER PLANE DRAWN PERPENDICULAR TOSAID BASE MEMBER HALF-WAY BETWEEN SAID OPPOSED SIDE MEMBERS, WHEREBYSAID PAIR OF ARMS AND SAID PAIR OF GUIDE LANCES COOPERATE TO DEFINE ALONGITUDINAL CHANNEL FOR RECEIVING AND CRADLING SAID SPADE-TYPE CONTACTELEMENT; AND AXIALLY OFFSET MEANS CONNECTED TO SAID BASE MEMBER FORHOLDING SAID CONDUCTOR, SAID OFFSET MEANS BEING SPACED FROM THELONGITUDINAL AXIS OF SAID CHANNEL SO AS TO LEAVE SPACE FOR A SECONDCONNECTOR TO BE SLIPPED ONTO SAID PROTRUDING CONTACT ELEMENT.